Some of the particles, if any are left (for usually they are dissipated in vapor in the upper regions of the air), sift down upon our planet in the form of fine dust. From the top of a high mountain Dr. Reichenbach collected dust which had never been touched by spade or pick-ax; and in analysis he found this dust to consist of almost identically the same elements as those of which meteoric stones are composed—nickel, cobalt, iron, and phosphorus. Dr. Phipson, in his interesting work on _Meteors, Aërolites, and Shooting Stars_, remarks that “when a glass covered with pure glycerine is exposed to a strong wind, late in November, it receives a number of _black angular particles_, which can be dissolved in strong hydrochloric acid, and produces yellow chloride of _iron_ upon the glass plate.” It is a strange thought that the air which sifts in through the window, and settles on the tables and chairs, nay even the very air we breathe, may contain particles of matter which have at one time circled in meteoric form around the sun! Should this be the case, and if, as Professor Newcomb, the American astronomer, tells us, no less than 146,000 million meteoric particles fall on the earth during the course of a year, may we not infer that this means an increase in its mass? In my father’s book, _The Orbs Around Us_ (page 195), he writes: “If we assign a single grain as the weight of each meteor visible to the naked eye, we deduce fifteen millions of grains as the earth’s daily increase of weight. This is rather less than a ton. So that in the course of about three years the earth’s weight must increase (even on the very low value here assigned to a meteor’s weight) by a thousand tons; and in the course of the three thousand years during which astronomy has been a science the earth’s weight must have increased a million tons. This is a mere trifle compared with the earth’s own weight, which is 6,000 millions of millions of times greater. Indeed, it may easily be shown that the actual increase of the earth’s radius in this interval of 3,000 years, would be about the 70,000,000th part of an inch.” From time immemorial legend and superstition have interwoven themselves around these small members of the solar system as they silently and swiftly sweep across the vault of heaven, vanishing mysteriously as though extinguished by some invisible hand. Dante describes them: “As oft along the still and pure serene At nightfall glides a sudden trail of fire, Attracting with involuntary heed The eye to follow it, erewhile it rest And seems some star that shifted place in heaven.”